Power Control Method and Terminal

ABSTRACT

A power control method includes obtaining, by a first terminal, parameter information required for power control, where the parameter information includes at least one of a first parameter, a second parameter, and a third parameter, and determining, by the first terminal based on the parameter information, uplink transmit power used when uplink transmission is performed on a target beam or a target beam pair; where the first parameter includes a beam reception gain of a network device and/or a beam sending gain of the first terminal, where the second parameter is used to indicate interference caused by a second terminal to the first terminal on the target beam, and where the third parameter includes beam-specific target power and/or terminal-specific target power.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.16/349,429, filed on May 13, 2019, which is a national stage ofInternational Application No. PCT/CN2017/071015, filed on Jan. 12, 2017,which claims priority to Chinese Patent Application No. 201611000177.7,filed on Nov. 14, 2016. All of the aforementioned applications arehereby incorporated by reference in their entireties.

TECHNICAL FIELD

Embodiments relate to the field of communications technologies, and inparticular, to a power control method and a terminal.

BACKGROUND

A millimeter wave refers to an electromagnetic wave that has amillimeter-level wavelength, and a carrier frequency of the millimeterwave is approximately between 30 GHz and 300 GHz. Because a highercarrier frequency indicates higher signal bandwidth and a higher datatransmission rate that can be implemented, a high frequency band greaterthan 6 GHz is introduced into a 5G (5th-Generation, fifth generationmobile communications technology) network for communication, in order touse transmission characteristics of high bandwidth and a high rate ofthe millimeter wave. However, another characteristic of the millimeterwave is that attenuation in the air is relatively high, that is, pathloss is relatively high. Therefore, generally, transmission is performedusing a beam (beam) to improve transmission distance and transmissionintegrity.

In an LTE (Long Term Evolution) system, when a terminal performs uplinktransmission on a wireless access device, uplink power control (PowerControl, PC) needs to be performed first, so as to ensure quality ofsending data on an uplink channel, and minimize interference to anotherterminal in the system. Power control of a PUSCH (Physical Uplink SharedChannel) is used as an example. The terminal estimates, based on thetransmit power of the wireless access device and received signalstrength of a current terminal, a path loss of current transmission, andthen adds the path loss to a preset power control formula to determinetransmit power of data transmission on the PUSCH. If the path loss isgreater, the determined transmit power is greater.

However, when a wireless network terminal is used as a transmitter tosend data using a beam, to adapt to different channel transmission orchannel change conditions, beam width may be adjusted, in order toadjust beam sending gain. When the terminal is used as a receiver toreceive data using a beam, to adapt to different channel transmission orchannel change conditions, beam width may be adjusted, in order toadjust beam reception gain. The beam sending gain and the beam receptiongain affect estimation of the path loss by the terminal, which causespath loss deviation. Therefore, corresponding adjustment needs to bemade to the transmit power in the transmission process. If the terminalestimates the path loss based on the power control method of theexisting LTE system, the obtained estimated path loss deviates fromactual path loss, and consequently, the determined transmit powerdeviates from actually required transmit power.

SUMMARY

Embodiments provide a power control method and a terminal to improveaccuracy of transmit power used by the terminal during uplinktransmission.

The following technical solutions are used to achieve the foregoingobjective.

According to a first aspect, an embodiment provides a power controlmethod, including: obtaining, by a first terminal, parameter informationrequired for power control, where the parameter information includes atleast one of a first parameter, a second parameter, and a thirdparameter; and then determining, by the first terminal based on theparameter information, uplink transmit power used when uplinktransmission is performed on a target beam or a target beam pair.

The first parameter includes a beam reception gain of the network deviceand/or a beam sending gain of the first terminal. In this way, whencalculating the uplink transmit power, the first terminal may determinemore accurate path loss compensation using the beam reception gain ofthe network device and/or the beam sending gain of the first terminal toimprove accuracy of the uplink transmit power.

The second parameter includes a value of interference caused by a secondterminal to the first terminal on the target beam. In this way, whencalculating the uplink transmit power, the first terminal may determinemore accurate path loss compensation using the foregoing interferencevalue to improve accuracy of the uplink transmit power.

The third parameter includes beam-specific target power and/orterminal-specific target power. In this way, when calculating the uplinktransmit power, the first terminal may determine more accurate targetpower value using the foregoing third parameter to improve accuracy ofthe uplink transmit power.

According to one aspect, the first parameter further includes a firstcompensation factor of the beam sending gain of the first terminaland/or a first compensation factor of the beam reception gain of thenetwork device, where the first compensation factor is any value greaterthan or equal to 0 and less than or equal to 1.

According to another aspect, the second parameter further includes asecond compensation factor of the foregoing interference value, wherethe second compensation factor is any value greater than or equal to 0and less than or equal to 1; and the interference value is used toindicate interference that is detected by the network device on thetarget beam that is caused by uplink transmission of the second terminalto uplink transmission of the first terminal.

According to another aspect, the method further includes: obtaining, bythe first terminal, a fourth parameter, where the fourth parameterincludes a beam sending gain of the network device and/or a beamreception gain of the first terminal, so that the first terminal mayfirst determine a path loss of the target beam or the target beam pairbased on the fourth parameter, and then the first terminal determinesthe uplink transmit power based on the path loss and the foregoingparameter information using a preset power control formula.

According to another aspect, making a determination of a path loss ofthe target beam or the target beam pair based on the fourth parameterincludes determining, by the first terminal, the path loss of the targetbeam or the target beam pair based on at least one of the transmit powerof the network device, the beam sending gain of the network device,received signal strength of the first terminal, and the beam receptiongain of the first terminal.

According to another aspect, after the determining, by the firstterminal, a path loss of the target beam or the target beam pair basedon the fourth parameter, the method further includes correcting, by thefirst terminal, the path loss using the first parameter, where thecorrected path loss is a difference between the path loss and the firstparameter before the correction.

According to another aspect, the foregoing uplink transmission refers toat least one of, transmission on a PUSCH, transmission on a PUCCH(Physical Uplink Control Channel), transmission on a PRACH (PhysicalRandom Access Channel), and transmission of an SRS (Sounding ReferenceSignal),

According to another aspect, the first parameter may be determined basedon at least one of a service type of to-be-transmitted data, an uplinkchannel type, a width of the target beam, a number of a subframe, anumber of the target beam, a number of the target beam pair, a number ofa carrier, and a number of a subcarrier.

According to another aspect, the parameter information further includesa fifth parameter, and the fifth parameter is used to indicate anadjustment value of closed-loop power control for performing uplinktransmission on the target beam or the target beam pair; where the fifthparameter is a sum of an adjustment value and an offset that are usedwhen power control is performed in a target subframe, and the targetsubframe is a subframe that is of a same type as a current subframe andthat is followed by the current subframe.

According to another aspect, the obtaining, by a first terminal,parameter information required for power control includes obtaining theparameter information using at least one of RRC (Radio Resource Control)signaling, MAC (Media Access Control) signaling, and physical layersignaling.

According to another aspect, the parameter information includes thefirst parameter, and the obtaining parameter information required forpower control includes obtaining, by the first terminal, the firstparameter using TPC (Transmit Power Control) signaling in a PDCCH, orobtaining, the first parameter by using signaling used for closed-looppower control.

According to another aspect, the parameter information includes thethird parameter, and obtaining parameter information required for powercontrol includes obtaining, using the physical layer signaling, thethird parameter sent by the network device, where the third parametercarries the first parameter.

According to another aspect, the parameter information further includesconfiguration information of target RSRP (Reference Signal ReceivedPower), and the configuration information of the target RSRP includesduration of the target beam, a quantity of samples of the target beam,or information about instantaneous RSRP.

According to another aspect, the configuration information of the targetRSRP is carried in the RRC signaling or the MAC signaling.

According to another aspect, the method further includes activating, bythe first terminal based on physical layer signaling sent by the networkdevice, the target RSRP indicated by the configuration information ofthe target RSRP.

According to another aspect, an embodiment provides a terminal, wherethe terminal is a first terminal, and the first terminal includes: anobtaining unit, configured to obtain parameter information required forpower control, where the parameter information includes at least one ofa first parameter, a second parameter, or a third parameter; and adetermining unit, configured to determine, based on the parameterinformation, uplink transmit power used when uplink transmission isperformed on a target beam or a target beam pair; where the firstparameter includes a beam reception gain of a network device and/or abeam sending gain of the first terminal; the second parameter includes avalue of interference caused by a second terminal to the first terminalon the target beam, and the second terminal includes one or moreterminals other than the first terminal; and the third parameterincludes beam-specific target power and/or terminal-specific targetpower. The beam-specific target power is a target power value set by thenetwork device for the target beam or the target beam pair, and theterminal-specific target power is a target power value that is set bythe network device for the first terminal on the target beam or thetarget beam pair.

According to one aspect, the first parameter further includes a firstcompensation factor of the beam sending gain of the first terminaland/or a first compensation factor of the beam reception gain of thenetwork device, where the first compensation factor is any value greaterthan or equal to 0 and less than or equal to 1.

According to another aspect, the second parameter further includes asecond compensation factor of the interference value, where the secondcompensation factor is any value greater than or equal to 0 and lessthan or equal to 1; and the interference value is used to indicateinterference that is detected by the network device on the target beamand that is caused by uplink transmission of the second terminal touplink transmission of the first terminal.

According to another aspect, the obtaining unit is further configured toobtain a fourth parameter, where the fourth parameter includes a beamsending gain of the network device and/or a beam reception gain of thefirst terminal, and the determining unit is configured to determine apath loss of the target beam or the target beam pair based on the fourthparameter, and determine the uplink transmit power based on the pathloss and the parameter information using a preset power control formula.

According to another aspect, the determining unit is configured todetermine the path loss of the target beam or the target beam pair basedon at least one of: transmit power of the network device; the beamsending gain of the network device in the fourth parameter; receivedsignal strength of the first terminal; and the beam reception gain ofthe first terminal in the fourth parameter.

According to another aspect, the determining unit is further configuredto correct the path loss using the first parameter, where the correctedpath loss is a difference between the path loss and the first parameterbefore the correction.

According to another aspect, the first parameter is determined based onat least one of a service type of to-be-transmitted data, an uplinkchannel type, a width of the target beam, a number of a subframe, anumber of the target beam, a number of the target beam pair, a number ofa carrier, and a number of a subcarrier.

According to another aspect, the parameter information further includesa fifth parameter, and the fifth parameter is used to indicate anadjustment value of closed-loop power control for performing uplinktransmission on the target beam or the target beam pair; where the fifthparameter is a sum of an adjustment value and an offset that are usedwhen power control is performed in a target subframe, and the targetsubframe is a subframe that is of a same type as a current subframe andthat is followed by the current subframe.

According to another aspect, the obtaining unit is configured to obtainthe parameter information using at least one of RRC signaling, MACsignaling, and physical layer signaling.

According to another aspect, the obtaining unit is configured to: obtainthe first parameter using TPC signaling in a PDCCH; or obtain the firstparameter using signaling used for closed-loop power control.

According to another aspect, the obtaining unit is configured to obtain,using the physical layer signaling, the third parameter sent by thenetwork device, where the third parameter carries the first parameter.

According to another aspect, the parameter information further includesconfiguration information of a target RSRP, and the configurationinformation of the target RSRP includes duration of the target beam, aquantity of samples of the target beam, or information about aninstantaneous RSRP, and the determining unit is further configured toactivate, based on the physical layer signaling sent by the networkdevice, the target RSRP indicated by the configuration information ofthe target RSRP.

According to another aspect, an embodiment provides a terminal, wherethe terminal is a first terminal that includes a processor, a memory, abus, and a communications interface. The processor is configured toobtain parameter information required for power control through thecommunications interface, where the parameter information includes atleast one of a first parameter, a second parameter, or a thirdparameter. The processor is further configured to determine, based onthe parameter information, uplink transmit power used when uplinktransmission is performed on a target beam or a target beam pair, wherethe first parameter includes a beam reception gain of a network deviceand/or a beam sending gain of the first terminal, the second parameterincludes a value of interference caused by a second terminal to thefirst terminal on the target beam, and the second terminal includes oneor more terminals other than the first terminal, and the third parameterincludes beam-specific target power and/or terminal-specific targetpower. The beam-specific target power is a target power value set by thenetwork device for the target beam or the target beam pair, and theterminal-specific target power is a target power value that is set bythe network device for the first terminal on the target beam or thetarget beam pair.

According to another aspect, the processor is further configured toobtain a fourth parameter through the communications interface, wherethe fourth parameter includes a beam sending gain of the network deviceand/or a beam reception gain of the first terminal, and the processor isconfigured to determine a path loss of the target beam or the targetbeam pair based on the fourth parameter and determine the uplinktransmit power based on the path loss and the parameter informationusing a preset power control formula.

According to another aspect, the processor is configured to determinethe path loss of the target beam or the target beam pair based on atleast one of, transmit power of the network device, the beam sendinggain of the network device in the fourth parameter, received signalstrength of the first terminal, and the beam reception gain of the firstterminal in the fourth parameter.

According to another aspect, the processor is further configured tocorrect the path loss using the first parameter, where the correctedpath loss is a difference between the path loss and the first parameterbefore the correction.

According to another aspect, the processor is configured to obtain theparameter information by invoking the communications interface and usingat least one of RRC signaling, MAC signaling, and physical layersignaling.

According to another aspect, the processor is configured to: obtain thefirst parameter by invoking the communications interface and using TPCsignaling in a PDCCH; or obtain the first parameter using signaling usedfor closed-loop power control.

According to another aspect, the processor is configured to obtain, byinvoking the communications interface and using the physical layersignaling, the third parameter sent by the network device, where thethird parameter carries the first parameter.

According to another aspect, the parameter information further includesconfiguration information of a target reference signal received powerRSRP, and the configuration information of the target RSRP includesduration of the target beam, a quantity of samples of the target beam,or information about an instantaneous RSRP The processor is furtherconfigured to activate, based on the physical layer signaling sent bythe network device, the target RSRP indicated by the configurationinformation of the target RSRP.

According to another aspect, an embodiment provides a computer storagemedium configured to store a computer software instruction implementedby the foregoing first terminal, where the computer storage instructionincludes a program designed to execute the foregoing aspect.

According to another aspect, an embodiment provides a computer program.The computer program includes an instruction whereby a computer executesthe computer program, and performs any one of the power control methodsin the foregoing first aspect.

In the embodiments disclosed, names of the first terminal, the secondterminal and the network device impose no limitation on devices orfunction modules. In actual implementation, these devices or functionmodules may be represented by other names. All devices or functionmodules with functions similar to those in the disclosure fall withinthe scope defined by the claims and equivalent technologies.

In addition, for a technical effect brought by any design implementationin the disclosed aspects, refer to technical effects brought bydifferent design manners in the first aspect. Details are not describedherein again.

These and other aspects of the disclosure are further illustrated andcomprehensible in descriptions of the following embodiments.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a schematic structural diagram of a power control systemaccording to an embodiment;

FIG. 2 is schematic structural diagram 1 of a terminal according to anembodiment;

FIG. 3 is a schematic structural diagram of a network device accordingto an embodiment;

FIG. 4 is a schematic flowchart of a power control method according toan embodiment;

FIG. 5 is schematic structural diagram 2 of a terminal according to anembodiment; and

FIG. 6 is schematic structural diagram 3 of a terminal according to anembodiment.

DESCRIPTION OF EMBODIMENTS

The following describes the technical solutions in detail with referenceto the accompanying drawings in the disclosed exemplary embodiments.

In addition, the terms “first” and “second” are merely intended for apurpose of description, and shall not be understood as an indication orimplication of relative importance or implicit indication of the numberof indicated technical features. Therefore, a feature limited by “first”or “second” may explicitly or implicitly include one or more features.In the description, “a plurality of” means two or at least two unlessotherwise stated.

The term “and/or” in this specification describes only an associationrelationship for describing associated objects and represents that threerelationships may exist. For example, A and/or B may represent thefollowing three cases: Only A exists, both A and B exist, and only Bexists. In addition, the character “/” in this specification generallyindicates an “or” relationship between the associated objects.

An embodiment provides a power control method, and the method may beapplied to a power control system shown in FIG. 1. The system includesat least one terminal 11 and a network device 12. Wireless transmissionmay be performed between the terminal 11 and the network device 12 usinga beam, for example, a target beam shown in FIG. 1.

The terminal 11 may be UE (user equipment, user equipment) in a 5Gnetwork, or may be any UE in LTE or another network. For example, theterminal 11 may be a mobile phone, a tablet, a notebook computer, a UMPC(ultra-mobile personal computer, ultra-mobile personal computer), anetbook, a PDA (personal digital assistant, personal digital assistant),or the like. This is not limited in this embodiment.

The network device 12 may be any base station, a new radio eNB (newradio eNB), a transmission and reception point (transmission andreception point, TRP), a macro base station, a micro base station, ahigh frequency base station, or the like in the 5G network. This is notlimited in this embodiment.

In an LTE system, when the terminal performs uplink transmission on thenetwork device, uplink transmit power may be calculated using a presetpower control formula. For example, when the uplink transmission isperformed on a PUSCH of a subframe i (i≥0), the terminal may calculate,using the following formula (1), uplink transmit power that needs to beused when uplink transmission is performed on the subframe i.

$\begin{matrix}{{P_{{PUSCH},c}(i)} = {\min\begin{Bmatrix}\begin{matrix}{{P_{{CMAX},c}(i)},} \\{{10\;{\log_{10}\left( {M_{{PUSCH},c}(i)} \right)}} + {P_{{O\text{-}{PUSCH}},c}(j)} +}\end{matrix} \\{{{\alpha_{c}(j)} \cdot {PL}_{c}} + {\Delta_{{TF},c}(i)} + {f_{c}(i)}}\end{Bmatrix}}} & (1)\end{matrix}$

P_(CMAX,c)(i) is a maximum transmit power of the terminal;

M_(PUSCH,c)(i) is a quantity of RBs (resource block, resource block)used for performing PUSCH transmission in a subframe i;

P_(O-PUSCH,c)(j) is a target power value that is semi-statically set bythe network device. The target power value is generally related tocell-specific target power and terminal-specific target power specifiedin the 3GPP protocol. A value of a parameter j is related to an uplinktransmitted data packet. When a semi-persistent grant data packet istransmitted, j=0; when a dynamically scheduled grant data packet istransmitted, j=1; or when a random access response grant data packet istransmitted, j=2;

PL_(c) is a path loss estimated when the terminal performs the uplinktransmission, α_(c) is a compensation factor of the path loss, and0≤α_(c)≤1;

Δ_(TF,c)(i) is an MCS-based power adjustment value; and

f_(c)(i) is an adjustment value used when power control is performed inthe subframe i.

The terminal may calculate, using the foregoing parameters, the uplinktransmit power P_(PUSCH,c)(i) for performing the uplink transmission onthe subframe i.

A millimeter wave with a higher carrier frequency is introduced to the5G network for communication, so as to use transmission characteristicsof high bandwidth and a high rate of the millimeter wave. However, toovercome a disadvantage that millimeter wave attenuation is relativelyhigh in the air, the terminal and/or the network device may perform theuplink transmission by adjusting a width of the beam and using the beamas a transmission medium. The width of the beam is generally less than awidth of a beam in a conventional LTE system.

When the terminal uses the foregoing beam to transmit uplink data, thereis a specific beam sending gain. In addition, when the base station usesthe beam to receive the uplink data, there is a specific beam receptiongain. The beam sending gain and the beam reception gain may reduce pathloss compensation that is actually required in a transmission process,and in this case, if the uplink transmit power is still calculated usingthe foregoing formula (1), the path loss compensation determined by theterminal is greater than an actual requirement. Therefore, thecalculated uplink transmit power is relatively high, which not onlyincreases power consumption of the terminal, but also increasesinterference to another terminal in the system.

Therefore, an embodiment provides a power control method. A firstterminal is used as an example. When determining uplink transmit power,the first terminal may first obtain parameter information required forpower control, and then determine, based on the parameter information,uplink transmit power used when uplink transmission is performed on atarget beam (or a target beam pair). The target beam is a beam used whenthe first terminal subsequently performs the uplink transmission, andthe target beam pair is a beam used when the first terminal subsequentlyperforms the uplink transmission or a beam used when the network devicereceives data in the uplink transmission process.

The parameter information includes at least one of the followingparameters: a first parameter, a second parameter, and a thirdparameter.

The foregoing first parameter includes a beam reception gain of thenetwork device and/or a beam sending gain of the first terminal. In thisway, when calculating the uplink transmit power, the first terminal maydetermine more accurate path loss compensation using the beam receptiongain of the network device and/or the beam sending gain of the firstterminal, so as to improve accuracy of the uplink transmit power.

The second parameter includes a value of interference that is caused bythe second terminal (the second terminal includes one or more terminalsother than the first terminal) to the first terminal on the target beam.In this way, when calculating the uplink transmit power, the firstterminal may determine more accurate path loss compensation using theforegoing interference value, so as to improve accuracy of the uplinktransmit power.

The third parameter includes beam-specific target power and/orterminal-specific target power, where the beam-specific target power isa target power value set by the network device for the target beam (orthe target beam pair), and the terminal-specific target power is atarget power value (the foregoing target power value may be referred toas nominal power) set by the network device for the first terminal onthe target beam (or the target beam pair). Because the beam-specifictarget power is not considered in P_(O-PUSCH,c) in the formula (1) inthe prior art, in this embodiment, when calculating the uplink transmitpower, the first terminal may determine more accurate P_(O-PUSCH,c),that is P_(O-PUSCH,c)′, using the foregoing third parameter, therebyimproving accuracy of uplink transmit power. P_(O-PUSCH,c)′ may be atleast one of or a sum of two or more of the cell-specific target power,the beam-specific target power, and the terminal-specific target power.

For example, the first terminal may obtain one or more parameters in theforegoing parameter information from the network device using at leastone of RRC (Radio Resource Control) signaling, MAC (Media AccessControl, Media Access Control) signaling, and physical layer signaling.This is not limited in this embodiment.

It may be understood that, after obtaining the one or more parameters inthe foregoing parameter information, the first terminal may still usethe method in the prior art to obtain another parameter required fordetermining the uplink transmit power, for example, M_(PUSCH,c)(i),P_(CMAX,c)(i), or the like in the formula (1). This is not limited inthis embodiment.

In addition, in the foregoing embodiment, transmission on the PUSCH isonly used as an example for description. It should be understood thatthe foregoing power control method may be further applied totransmission on a PUCCH (Physical Uplink Control Channel), transmissionon a PRACH (Physical Random Access Channel), transmission of an SRS(Sounding Reference Signal), and the like. In subsequent embodiments,details are described with reference to specific embodiments. Therefore,details are not described herein.

For a hardware structure of a terminal 11 (for example, the foregoingfirst terminal) in this embodiment, refer to components of the terminal11 shown in FIG. 2.

As shown in FIG. 2, the terminal 11 may include components such as an RF(radio frequency, radio frequency) circuit 320, a memory 330, an inputunit 340, a display unit 350, a gravity sensor 360, an audio circuit370, a processor 380, and a power supply 390. A person skilled in theart may understand that a structure of the terminal shown in FIG. 5 doesnot constitute a limitation on the terminal 11, may include more orfewer components than those shown in FIG. 6, combine some components, orhave different component deployment.

The following describes each component of the terminal 11 in detail withreference to FIG. 2.

The RF circuit 320 may be configured to receive or send a signal in aninformation receiving or sending process or a call process. Inparticular, after receiving downlink information of a network device 12,the RF circuit 320 sends the downlink information to the processor 380for processing, and sends uplink data to the network device 12.Generally, the RF circuit includes but is not limited to an antenna, atleast one amplifier, a transceiver, a coupler, an LNA (low noiseamplifier, low noise amplifier), a duplexer, and the like. In addition,the RF circuit 320 may further communicate with a network and anotherdevice through wireless communication.

The memory 330 may be configured to store a software program and amodule, and the processor 380 performs various function applications ofthe terminal 11 and processes data by running the software program andthe module that are stored in the memory 330.

The input unit 340 may be configured to: receive input digital orcharacter information, and generate key signal input related to usersetting and function control of the terminal 11. The input unit 340 mayinclude a touch panel 341 and another input device 342.

The display unit 350 may be configured to display information input bythe user or information provided for the user, and various menus of theterminal 11. The display unit 350 may include a display panel 351.Optionally, the display panel 351 may be configured using an LCD (LiquidCrystal Display, liquid crystal display), an OLED (OrganicLight-Emitting Diode, organic light-emitting diode), or the like.

The terminal 11 may further include the gravity sensor (gravity sensor)360 and another sensor, for example, an optical sensor, a gyroscope, abarometer, a hygrometer, a thermometer, and an infrared sensor. Detailsare not described herein.

The audio circuit 370, a loudspeaker 371, and a microphone 372 mayprovide an audio interface between the user and the terminal 11. Theaudio circuit 370 may transmit, to the loudspeaker 371, a receivedelectrical signal obtained after audio data conversion, and theloudspeaker 371 converts the electrical signal to a sound signal foroutput. In addition, the microphone 372 converts a collected soundsignal to an electrical signal, and the audio circuit 370 receives theelectrical signal, converts the electrical signal to audio data, andoutputs the audio data to the RF circuit 320, to send the audio data to,for example, another terminal device, or outputs the audio data to thememory 330 for further processing.

The processor 380 is a control center of the terminal 11, and connectsto various parts of the terminal 11 using various interfaces and lines.The processor 380 performs various functions of the terminal 11 andprocesses data by running or executing the software program and/or themodule stored in the memory 330 and by invoking data stored in thememory 330, so as to perform overall monitoring on the terminal 11.Optionally, the processor 380 may include one or more processing units.

Although not shown in the figure, the terminal 11 may further include apower supply, a Wi-Fi (Wireless Fidelity, Wireless Fidelity) module, aBluetooth module, and the like. Details are not described herein.

For a hardware structure of the network device 12 in this embodiment,refer to components of the network device 12 shown in FIG. 3. As shownin FIG. 3, the network device 12 includes a BBU (English: Base BandUnit, baseband processing unit), an RRU (English: Radio Remote Unit,radio remote unit), and an antenna. The BBU and the RRU may be connectedusing an optical fiber, and the RRU is further connected to the antennausing a coaxial cable and a power splitter (coupler). Generally, one BBUmay be connected to a plurality of RRUs.

The RRU may include four modules: a digital intermediate frequencymodule, a transceiver module, a power amplification module, and afiltering module. The digital intermediate frequency module isconfigured to perform modulation and demodulation of opticaltransmission, digital up- and down-frequency conversion,digital-to-analog conversion, and the like. The transceiver modulecompletes conversion from an intermediate frequency signal to a radiofrequency signal. After being amplified by the power amplificationmodule and filtered by the filtering module, the radio frequency signalis transmitted using the antenna.

The BBU is configured to complete a baseband processing function(encoding, multiplexing, modulation, spread spectrum, and the like) of aUu interface (that is, an interface between the terminal 11 and thenetwork device 12), an interface function of a logical interface betweenan RNC (English: Radio Network Controller, radio network controller) andthe network device 12, a signaling processing function, local and remoteoperation and maintenance functions, and working status monitoring andalarm information reporting functions of a network device 12 system.

The following describes a power control method according to anembodiment in detail with reference to in FIG. 4.

401. A first terminal obtains parameter information required for powercontrol, where the parameter information includes at least one of afirst parameter, a second parameter, and a third parameter.

402. The first terminal determines, based on the parameter information,uplink transmit power used when uplink transmission is performed on atarget beam (or a target beam pair).

In a possible implementation, the foregoing parameter informationincludes the first parameter, and the first parameter includes a beamreception gain of a network device and/or a beam sending gain of thefirst terminal.

When the network device uses the target beam to receive uplink data andthe first terminal uses an omnidirectional beam to send the uplink data,the foregoing first parameter may include a beam reception gain G_(R) ofthe network device; when the network device uses the target beam toreceive uplink data and the first terminal also uses the target beam tosend the uplink data, the foregoing first parameter may include the beamreception gain G_(R) of the network device and a beam sending gain G_(T)of the first terminal.

The beam sending gain G_(T) of the first terminal may be determined bythe first terminal itself, or may be obtained by the first terminal fromthe network device. The beam reception gain G_(R) of the network devicemay be obtained by the first terminal from the network device.

In this case, for a subframe i, uplink transmit power for performinguplink transmission on a PUSCH may be the following formula (2):

$\begin{matrix}{{P_{{PUSCH},c}(i)} = {\min\begin{Bmatrix}\begin{matrix}{{P_{{CMAX},c}(i)},} \\{{10\;{\log_{10}\left( {M_{{PUSCH},c}(i)} \right)}} + {P_{{O\text{-}{PUSCH}},c}(j)} +}\end{matrix} \\{{{\alpha_{c}(j)} \cdot {PL}_{c}} - G + {\Delta_{{TF},c}(i)} + {f_{c}(i)}}\end{Bmatrix}}} & (2)\end{matrix}$

G=G_(R), or G_(T), or G_(T)+G_(R); other parameters in the formula (2),for example, M_(PUSCH,c)(i), M_(PUSCH,c)(i) P_(O-PUSCH,c)(j),Δ_(TF,c)(i) and f_(c)(i), may be determined using a related method inthe prior art.

In the foregoing formula (2), α_(c)(j)·PL_(c)−G may be used for new pathloss compensation; that is, when a path loss is calculated using theformula (2), the beam reception gain G_(R) of the network device and/orthe beam sending gain G_(T) of the first terminal are/is considered, sothat impact caused by the first parameter G on the uplink transmit poweris excluded in the path loss compensation, so as to improve accuracy ofthe uplink transmit power.

Further, the first parameter may include a first compensation factor ofthe beam sending gain of the first terminal and/or a first compensationfactor of the beam reception gain of the network device, where the firstcompensation factor may be represented by β, and 0≤β≤1; that is, thefirst compensation factor β is any value in [0, 1] (which includes 0 and1), and in this case, the first parameter includes G and β.

In this case, for the subframe i, the uplink transmit power forperforming the uplink transmission on the PUSCH may be the followingformula (3):

$\begin{matrix}{{{P_{{PUSCH},c}(i)} = {\min\begin{Bmatrix}\begin{matrix}{{P_{{CMAX},c}(i)},} \\{{10\;{\log_{10}\left( {M_{{PUSCH},c}(i)} \right)}} + {P_{{O\text{-}{PUSCH}},c}(j)} +}\end{matrix} \\{{{\alpha_{c}(j)} \cdot {PL}_{c}} - \beta + G + {\Delta_{{TF},c}(i)} + {f_{c}(i)}}\end{Bmatrix}}}{{{\beta \cdot G} = {\beta \cdot G_{T}}},{{{or}\mspace{14mu}{\nu \cdot G}} = {\beta \cdot G_{R}}},{{{or}\mspace{14mu}{\beta \cdot G}} = {\beta \cdot {\left( {G_{T} + G_{R}} \right).}}}}} & (3)\end{matrix}$

In addition, different first compensation factors may be set for thebeam reception gain G_(R) of the network device and the beam sendinggain G_(T) of the first terminal; for example, the first compensationfactor of the beam reception gain G_(R) of the network device is β₁, andthe first compensation factor of the beam sending gain G_(T) of thefirst terminal is β₂. In this case, the foregoing formula (3) may bedeformed into the following formula (4), that is:

$\begin{matrix}{{P_{{PUSCH},c}(i)} = {\min\begin{Bmatrix}\begin{matrix}{{P_{{CMAX},c}(i)},} \\{{10\;{\log_{10}\left( {M_{{PUSCH},c}(i)} \right)}} + {P_{{O\text{-}{PUSCH}},c}(j)} +}\end{matrix} \\{{{\alpha_{c}(j)} \cdot {PL}_{c}} - \left( {{\beta_{1} \cdot G_{R}} + {\beta_{2} \cdot G_{T}}} \right) + {\Delta_{{TF},c}(i)} + {f_{c}(i)}}\end{Bmatrix}}} & (4)\end{matrix}$

It should be noted that, in the foregoing embodiment, the transmissionon the PUSCH is only used as an example for description. The powercontrol method provided in this embodiment may be further applied totransmission on a PUCCH, transmission on a PRACH, transmission of anSRS, and the like. This is not limited in this embodiment.

For example, uplink transmit power of the transmission on the PUCCH maybe the following formula (5):

$\begin{matrix}{{P_{{PUCCH},c}(i)} = {\min\begin{Bmatrix}\begin{matrix}{{P_{{CMAX},c}(i)},} \\{P_{0\text{-}{PUCCH}} + {PL}_{c} + {h\left( {n_{CQI},{n_{HARQ}n_{SR}}} \right)} -}\end{matrix} \\{{\beta \cdot G} + {\Delta_{F\text{-}{PUCCH}}(F)} + {\Delta_{TxD}\left( F^{\prime} \right)} + {g(i)}}\end{Bmatrix}}} & (5)\end{matrix}$

Similar to the power control formula of the PUSCH, for example, theforegoing formula (3), P_(CMAX,c)(i) is a maximum transmit power of thefirst terminal, and P_(0-PUCCH) is a target power value that issemi-statically set by the network device. h(n_(CQI), n_(HARQ), n_(SR))is a value that depends on a PUCCH structure, where n_(CQI) represents aquantity of information bits of a CQI, and n_(HARQ) represents aquantity of bits of a HARQ; PL_(c) is a path loss estimated when thefirst terminal performs the uplink transmission; and g(i) is anadjustment value used when power control is performed in the subframe i.

β and G are the foregoing first parameters in the formula (5), where Gis the beam reception gain G_(R) of the network device and/or the beamsending gain G_(T) of the first terminal, and β is the firstcompensation factors/the first compensation factor of the beam sendinggain of the first terminal and/or the beam reception gain of the networkdevice.

For example, uplink transmit power of the transmission of the SRS may bethe following formula (6):

$\begin{matrix}{{P_{{SRS},c}(i)} = {\min\begin{Bmatrix}\begin{matrix}{{P_{{CMAX},c}(i)},} \\{{P_{{{SRS}\text{-}{OFFSET}},c}(m)} + {10{\log_{10}\left( M_{{SRS},c} \right)}} +}\end{matrix} \\{{P_{{O\text{-}{PUSCH}},c}(j)} + {{\alpha_{c}(j)} \cdot {PL}_{c}} - {\beta \cdot G} + {f_{c}(i)}}\end{Bmatrix}}} & (6)\end{matrix}$

P_(CMAX,c)(i) is the maximum transmit power of the first terminal;P_(SRS-OFFSET,c)(m) is a power offset of the SRS relative to the data ofPUSCH; M_(SRS,c) is transmission bandwidth of the SRS; f_(c)(i) is theadjustment value used when the power control is performed in thesubframe i; and P_(O-PUSCH,c)(j) is similar to P_(O-PUSCH,c)(j) informulas (1) to (4).

Similarly, β and G in the formula (6) are the foregoing firstparameters, where G is the beam reception gain G_(R) of the networkdevice and/or the beam sending gain G_(T) of the first terminal, and βis the first compensation factors/the first compensation factor of thebeam sending gain of the first terminal and/or the beam reception gainof the network device.

For ease of description, in subsequent embodiments, the transmission onthe PUSCH is used as an example for description.

Further, a specific value of β or G in the foregoing first parameter maybe determined by the first terminal based on at least one of a servicetype of to-be-transmitted data, an uplink channel type, a width of thetarget beam, a number of a subframe, a number of the target beam, anumber of the target beam pair, a number of a carrier, and a number of asubcarrier.

That is, the specific value of β or G may be specific to the servicetype of the to-be-transmitted data, and/or specific to the uplinkchannel type, and/or specific to the width of the target beam, and/orspecific to the target beam, and/or specific to the subframe, and/orspecific to the target beam pair, and/or specific to the carrier, and/orspecific to the subcarrier. For example, the service type may include aneMBB (Enhanced Mobile Broadband) service, an mMTC (Massive Machine TypeCommunication) service, and a URLLC (ultra-reliable and low latencycommunications) service.

The number of a subframe is used as an example. When the number of thesubframe is an odd number, β may be set to 1; or when the number of thesubframe is an even number, β may be set to 0. In this case, it may beconsidered that the subframe is divided into two types: an even numbertype and an odd number type. Certainly, a person skilled in the art maydivide the subframe into different types according to actual experienceor an algorithm. This is not limited in this embodiment.

Further, the first terminal may obtain a fourth parameter, where thefourth parameter includes a beam sending gain A_(T) of the networkdevice and/or a beam reception gain A_(R) of the first terminal. Inparticular, when calculating the uplink transmit power using any one ofthe formula (2) to the formula (6), the first terminal may furtherobtain the fourth parameter. The first terminal may obtain the fourthparameter while obtaining any parameter in the foregoing parameterinformation, or may separately obtain the fourth parameter. This is notlimited in this embodiment.

The beam reception gain A_(R) of the first terminal may be determined bythe first terminal itself, or may be obtained by the first terminal fromthe network device. The beam sending gain A_(T) of the network devicemay be obtained by the first terminal from the network device.

The first terminal may obtain the foregoing fourth parameter from thenetwork device using at least one of RRC (radio resource control, radioresource control) signaling, MAC (Media Access Control, Media AccessControl) signaling, and physical layer signaling. This is not limited inthis embodiment.

After obtaining the fourth parameter, the terminal may first determine apath loss of the target beam based on the fourth parameter, that is,PL_(c) in the foregoing formula (2) to formula (6).

PL_(c)=transmit power of the network device+the beam sending gain A_(T)of the network device−received signal strength of the first terminal+thebeam reception gain A_(R) of the first terminal. The calculation formulaof PL_(c) is further applicable to formulas (7) to (9) in subsequentembodiments.

In the foregoing calculation formula of PL_(c), a value of the receivedsignal strength of the first terminal may be any reference signalreceived value such as RSRP (reference signal received power, referencesignal received power), RSRQ (reference signal received quality,reference signal received quality), or RSSI (received signal strengthindication, received signal strength indication).

The received signal strength of the first terminal may be determinedbased on detection of a first target reference signal, where the firsttarget reference signal is a terminal-specific reference signal(reference signal, RS), for example, an aperiodic reference signal. Thefirst target reference signal may be triggered by the terminal ortriggered by a network device. Alternatively, the received signalstrength of the first terminal may be determined based on detection of asecond target reference signal. The second target reference signal is acell-specific reference signal, for example, a DRS (discovery RS,discovery signal), an SS (synchronization signal, synchronizationsignal), or a non-UE-specific DL RS (non-UE-specific downlink referencesignal). The second target reference signal may be specific to a sectorbeam or specific to a wide beam.

It may be understood that, in the foregoing calculation of PL_(c),configuration signaling delivered by the network device may indicate aspecific type of target reference signal (for example, the first targetreference signal or the second target reference signal) on whichcalculation or filtering performed by the received signal strength ofthe first terminal is based.

Further, the foregoing path loss PL_(c) may be corrected, for example, adifference between the foregoing path loss PL_(c) and the firstparameter G may be used as a corrected path loss. In this case, theforegoing formula (3) may be deformed into the following formula (7),that is:

$\begin{matrix}{{P_{{PUSCH},c}(i)} = {\min\begin{Bmatrix}\begin{matrix}{{P_{{CMAX},c}(i)},} \\{{10\;{\log_{10}\left( {M_{{PUSCH},c}(i)} \right)}} + {P_{{O\text{-}{PUSCH}},c}(j)} +}\end{matrix} \\{{\alpha_{c}(j)} + {\Delta_{{TF},c}(i)} + {f_{c}(i)}}\end{Bmatrix}}} & (7)\end{matrix}$

In this case, the first compensation factor β=α_(c)(j), and thecorrected path loss is PL_(c)−G.

In this case, the network device may directly send a related parameterof the corrected path loss to the first terminal, that is, implicitlysend the first parameter to the first terminal.

For example, the network device may send at least one of the following:

the transmit power of the network device+the beam sending gain A_(T) ofthe network device;

the transmit power of the network device+the beam sending gain A_(T) ofthe network device+the beam reception gain A_(R) of the first terminal;

the transmit power of the network device+the beam sending gain A_(T) ofthe network device+the beam reception gain A_(R) of the firstterminal−the beam sending gain G_(T) of the first terminal−the beamreception gain G_(R) of the network device; and

the transmit power of the network device+the beam sending gain A_(T) ofthe network device−the beam reception gain G_(R) of the network device.

In addition, because PL_(c)−G=(the transmit power of the networkdevice+the beam sending gain A_(T) of the network device−the receivedsignal strength of the first terminal+the beam reception gain of thefirst terminal)−(the beam sending gain G_(T) of the first terminal+thebeam reception gain G_(R) of the network device), if the beam sendinggain A_(T) of the network device is equal to the beam reception gainG_(R) of the network device, the network device does not need to sendA_(T) and G_(R) to the first terminal.

Further, to obtain the foregoing corrected path loss PL_(c)−G, thecalculation of target RSRP needs to be supported. Then, the firstterminal may further obtain configuration information of the target RSRPfrom the network device, where the configuration information may beduration of the target beam, a quantity of samples of the target beam,or a filtering type of the target beam. The duration is generally lessthan duration of an existing RSRP (for example, less than 10 ms), or thequantity of samples is generally less than a quantity of samples of anexisting RSRP (for example, fewer than 10 samples). Alternatively, theconfiguration information may be information about instantaneous RSRP,where the filtering type may be any one of layer-1 filtering, layer-2filtering, layer-3 filtering. The RSRP may be any reference signalreceived value such as the RSRQ or the RSSI. This is not limited in thisembodiment.

For example, the network device may add the configuration information ofthe target RSRP to the RRC signaling or the MAC signaling and send theconfiguration information of the target RSRP to the first terminal.

Subsequently, the first terminal may activate, based on the physicallayer signaling sent by the network device, RSRP calculation orderivation that is performed based on the configuration information ofthe target RSRP, to obtain a specific value of the target RSRP, and thencalculate the corrected path loss based on the specific value of thetarget RSRP.

Therefore, the first terminal may determine, based on the firstparameter in the parameter information and using the preset powercontrol formula, for example, any one of the foregoing formulas (2) to(7), the uplink transmit power used when the uplink transmission isperformed on the target beam (or the target beam pair).

In a possible implementation, the foregoing parameter informationincludes the second parameter, and the second parameter is used toindicate interference caused by the second terminal (the second terminalincludes one or more terminals other than the foregoing first terminal)to the first terminal on the target beam (or the target beam pair).

For example, the second parameter may be a value I of interference thatis detected by the network device on the target beam or the target beampair and that is caused by uplink transmission of the second terminal touplink transmission of the first terminal.

Further, the second parameter may include a second compensation factor μof the interference value I, where 0≤μ≤1.

In this case, if the parameter information includes both the foregoingfirst parameter (for example, the foregoing G and β) and the foregoingsecond parameter (for example, the foregoing I and μ), for the subframei, the uplink transmit power for performing uplink transmission on thePUSCH may be the following formula (8), that is:

${P_{{PUSCH},c}(i)} = {\min\begin{Bmatrix}\begin{matrix}{{P_{{CMAX},c}(i)},} \\{{10\;{\log_{10}\left( {M_{{PUSCH},c}(i)} \right)}} + {P_{{O\text{-}{PUSCH}},c}(j)} +}\end{matrix} \\{{{\alpha_{c}(j)} \cdot {PL}_{c}} - \beta + G + {\mu \cdot I} + {\Delta_{{TF},c}(i)} + {f_{c}(i)}}\end{Bmatrix}}$

In the foregoing formula (8), α_(c)(j)·PL_(c)−β·G+μ·I may be used as anew path loss, that is PL′. In other words, when the path loss iscalculated using the formula (8), the beam reception gain G_(R) of thenetwork device and/or the beam sending gain G_(T) of the first terminal,and the interference caused by the second terminal to the first terminalon the target beam are considered, so that impact caused by the firstparameter and the second parameter on the uplink transmit power isexcluded in the newly calculated path loss, so as to further improveaccuracy of the uplink transmit power.

When the network device receives the uplink data using the target beamand the second terminal sends the uplink data using the omnidirectionalbeam, the foregoing interference value I may be a value of interferencecaused by the second terminal received by the network device to thefirst terminal on the target beam, where the interference includes abeam reception gain I_(R) of the network device; when the network devicereceives the uplink data using the target beam, and the second terminalsends the uplink data using the target beam, the foregoing interferencevalue I further includes a beam sending gain I_(T) generated by thesecond terminal on the target beam, for example, the foregoinginterference value I includes a sum of I_(R) and I_(T).

In addition, when the foregoing interference value I is determined, thetarget beam of the first terminal may detect the estimated value I ofthe interference caused by the uplink transmission of the secondterminal to the uplink transmission of the first terminal. In this case,I=_(I′)−X, where X is a path loss when a signal is transmitted from thefirst terminal to the network device, and X≥0.

For example, the first terminal may obtain at least one of the firstparameter, the second parameter, and the fourth parameter using thephysical layer signaling, that is, dynamically obtain at least one ofthe first parameter, the second parameter, or the fourth parameter. Forexample, the first parameter is obtained using TPC (transmit powercontrol, transmit power control) signaling in a PDCCH (physical downlinkcontrol channel, physical downlink control channel); or the foregoingfirst parameter is obtained using signaling used for closed-loop powercontrol.

When the first parameter is delivered using the signaling used forclosed-loop power control, the first parameter may be delivered inclosed-loop power control together with delta (delta) adjustment oroffset (delta) adjustment, or may be delivered together with Δ_(TF,c)(i)in formulas (1) to (8). This is not limited in this embodiment.

Similar to the foregoing first parameter, a specific value of the secondparameter or the fourth parameter may be determined by the firstterminal based on at least one of the service type of theto-be-transmitted data, the uplink channel type, the width of the targetbeam, the number of the subframe, the number of the target beam, thenumber of the target beam pair, the number of the carrier, and thenumber of the subcarrier.

Therefore, the first terminal may determine, based on the secondparameter in the parameter information and using the preset powercontrol formula, for example, the foregoing formula (8), the uplinktransmit power used when the uplink transmission is performed on thetarget beam (or the target beam pair).

In a possible implementation, the foregoing parameter informationincludes the third parameter, and the third parameter includesbeam-specific target power and/or terminal-specific target power.

The beam-specific target power is a target power value that is set bythe network device for the target beam (or the target beam pair); andthe terminal-specific target power is a target power value that is setby the network device for the first terminal on the target beam (or thetarget beam pair).

In the prior art, referring to formula (1), P_(O-PUSCH,c)(j) is thetarget power value that is semi-statically set by the network device,where the target power value is generally the cell-specific target powerand the terminal-specific target power specified in the 3GPP protocol.Terminal-specific target power in the prior art refers to a target powervalue that is set by the network device for the terminal.

However, in a millimeter wave application scenario, because acommunications medium such as the target beam is introduced, ifP_(O-PUSCH,c)(j) is still determined based on the foregoing method, thedetermined P_(O-PUSCH,c)(j) is inaccurate.

Therefore, in this embodiment, the third parameter is introduced whenP_(O-PUSCH,c)(j) is calculated, where the third parameter includes thebeam-specific target power and/or the terminal-specific target power.Certainly, the third parameter may further include the cell-specifictarget power. Therefore, the first terminal may determine a value ofP_(O-PUSCH,c)(j) based on at least one of the beam-specific targetpower, the terminal-specific target power, and the cell-specific targetpower, and further calculate the uplink transmit power using any one ofthe foregoing formulas (2) to (8), so as to improve accuracy of theuplink transmit power.

The value, P_(O-PUSCH,c)(j) may be a sum of the beam-specific targetpower and the terminal-specific target power, or may be a sum of thebeam-specific target power, the terminal-specific target power, and thecell-specific target power, or may be a sum of the terminal-specifictarget power and the cell-specific target power.

The beam-specific target power and the terminal-specific target powermay be determined based on the detection of the foregoing first targetreference signal and the path loss derived from the detection process.The first target reference signal may be triggered by the first terminalor triggered by the network device. The beam-specific target power maybe target power specific to one beam or a group of beams.

The cell-specific target power is determined based on the detection ofthe second target reference signal and the path loss derived from thedetection process. The second target reference signal may be specific tothe sector beam or the wide beam. This is not limited in thisembodiment.

Further, the foregoing beam-specific target power may be determined bythe first terminal based on at least one of the service type of theto-be-transmitted data, the uplink channel type, the width of the targetbeam, the number of the subframe, the number of the target beam, thenumber of the carrier, and the number of the subcarrier.

In a possible implementation, any one of the foregoing target power mayfurther include a beam gain. For example, the beam-specific target powermay include the received beam gain of the network device and/or the beamsending gain of the network device; the terminal-specific target powermay include the received beam gain of the terminal and/or the beamsending gain of the terminal.

The beam-specific target power and/or the terminal-specific target powermay be dynamically indicated using the physical layer signaling; thatis, different from the semi-statically configured target power in theexisting system, the beam-specific target power and/or theterminal-specific target power are dynamically notified using the PDCCH.

For any specific parameter value of the beam (or the beam pair), on thebeam (or the beam pair), the first terminal uses an uplink power controlparameter (that is, the foregoing parameter information) correspondingto the beam (or the beam pair) to determine the uplink transmit power.

The first terminal may perform corresponding uplink power control byapplying the corresponding uplink power control parameter to thecorresponding value that is specific to the service type of theto-be-transmitted data, and/or specific to the uplink channel type,and/or specific to the width of the target beam, and/or specific to thetarget beam, and/or specific to the subframe, and/or specific to thetarget beam pair, and/or specific to the carrier, and/or specific to thesubcarrier. In this embodiment, one or a combination of more than one ofthe foregoing configurations may be referred to as a set-specificconfiguration.

For example, the first terminal obtains, using the RRC signaling sent bythe network device, that a set of the beam-specific target power indifferent subframes is (−2, 3, 5). That is, a beam-specific target powercorresponding to a subframe of type 1 is −2, a beam-specific targetpower corresponding to a subframe of type 2 is 3, and a beam-specifictarget power corresponding to a subframe of type 3 is 5. In this case,the first terminal may determine a specific value of the beam-specifictarget power based on a type of a current subframe i.

For another example, the beam-specific target power is indicated by theRRC signaling as (−8, −4, −2, 3, 5, 6, 7); that is, the beam-specifictarget power corresponding to each of the beam 1 to the beam 7, and thefirst terminal performs PUSCH uplink transmission on the beam 3.Therefore, the first terminal may determine that the beam-specifictarget power corresponding to the beam 3 is 2, and then calculate theuplink transmit power using the foregoing formulas (2) to (8).

In addition, each set may be configured based on any one of subframes,frequency bands, subbands, and beams (or beam pairs) that are ofdifferent types. For example, a frequency band a, a subband b, asubframe c, and beams (or beam pairs) 0, 1, 5, and 6 are configured asset 1, and a frequency band a+1, a subband b+1, a subframe c+1, andbeams (or beam pairs) 2, 3, 4, 7, 8, and 9 are configured as a set 2.

Then, if the RRC signaling indicates that the beam-specific target powercorresponding to the set 1 is −8, and the beam-specific target powercorresponding to the set 2 is 6, for example, the RRC signalingindicates that the beam-specific target power is (−8, 6), in this case,if uplink transmission of the PUSCH needs to be performed on a resourcecorresponding to the set 2, the first terminal may use 6 as thebeam-specific target power, and then calculate the uplink transmit powerusing the foregoing formulas (2) to (8).

Further, the network device may add the foregoing first parameter to thethird parameter and send the third parameter to the first terminal. Forexample, the network device may use a difference betweenP_(O-PUSCH,c)(j) and the first parameter (for example, β*G) as the thirdparameter, and deliver the third parameter to the first terminal. Inthis case, the foregoing formula (3) may be deformed into the followingformula (9), that is:

$\begin{matrix}{{P_{{PUSCH},c}(i)} = {\min\begin{Bmatrix}\begin{matrix}{{P_{{CMAX},c}(i)},} \\{{10\;{\log_{10}\left( {M_{{PUSCH},c}(i)} \right)}} + {a\mspace{14mu}{third}\mspace{14mu}{parameter}} +}\end{matrix} \\{{{\alpha_{c}(j)} \times {PL}_{c}} + {\Delta_{{TF},c}(i)} + {f_{c}(i)}}\end{Bmatrix}}} & (9)\end{matrix}$

In this case, because the first parameter is already hidden in the thirdparameter, the network device does not need to send the first parameterto the first terminal.

Further, the foregoing parameter information may include a fifthparameter, where the fifth parameter is used to indicate an adjustmentvalue of closed-loop power control for performing the uplinktransmission on the target beam (or the target beam pair), that is,f_(c)(i) in the foregoing formulas (1) to (9).

When the uplink transmit power is calculated for the target beam (or thetarget beam pair) in an accumulation mode (accumulation mode),f_(c)(i)=f_(c)(y)+δ_(PUSCH,c)(i−K_(PUSCH)), and y>i, whereδ_(PUSCH,c)(i−K_(PUSCH)) is an offset, the offset may be carried in TPCsignaling delivered by the network device, f_(c)(i) is an adjustmentvalue used when power control is performed on a target subframe y, andthe target subframe y is a subframe that is of a same type as a currentsubframe i and that is followed by the current subframe i.

Correspondingly, when performing closed-loop power control adjustmentbased on the accumulation mode, if one or more options in the frequencyband, the subband, the subframe, and the beam (or the beam pair) are alldistinguished in advance, for example, the frequency band, the sub-band,the subframe, and the beam are all distinguished, when the firstterminal determines f_(c)(y), a subframe that is of a same type offrequency band, subband, subframe, and beam as the current subframe iand that is followed by the current subframe i should be used as thetarget subframe y.

For example, a subframe 1, a subframe 2, and a subframe 4 are subframesof a same type. If the current subframe is the subframe 4, a subframethat is of the same type as the current subframe 4 and that is followedby the current subframe 4 is the subframe 2, and in this case,f_(c)(4)=f_(c)(2)+δ_(PUSCH,c)(i−K_(PUSCH)).

It should be noted that a value of G or β in the foregoing formulas (2)to (9) may be a negative number, and in this case, G in the foregoingformulas (2) to (9) is −G and β·G is −β·G.

In addition, the power control method provided in this embodiment isapplicable to a scenario in which channels are reciprocal; that is, anuplink path loss used in the uplink power control may be estimated bymeasuring a downlink path loss derived from a value of downlink RSRP orRSRQ.

Therefore, the first terminal may determine, by obtaining the parameterinformation required for performing the power control, that is, at leastone of the first parameter, the second parameter, or the third parameterand using any one power control formula of the foregoing formulas (2) to(9), the uplink transmit power used when the uplink transmission isperformed on the target beam (or the target beam pair) in the millimeterwave system, so as to implement more accurate power control.

The foregoing mainly describes the solutions provided in the disclosedembodiments from the perspective of interaction between networkelements. It may be understood that to implement the foregoingfunctions, the terminal and the network device include correspondinghardware structures and/or software modules for performing thefunctions. A person of ordinary skill in the art should be easily awarethat, in combination with the examples described in the embodimentsdisclosed in this specification, units, algorithms steps may beimplemented by hardware or a combination of hardware and computersoftware. Whether a function is performed by hardware or hardware drivenby computer software depends on particular applications and designconstraints of the technical solutions. A person skilled in the art mayuse different methods to implement the described functions for eachparticular application, but it should not be considered that theimplementation goes beyond the scope of the present disclosure.

In the embodiments, the terminal and the like may be divided intofunction modules based on the foregoing method examples. For example,each function module may be obtained through division for acorresponding function, or two or more functions may be integrated intoone processing module. The integrated module may be implemented in aform of hardware, or may be implemented in a form of a software functionmodule. It should be noted that the module division in the disclosedexemplary embodiments is merely logical function division. There may beother manners of division in actual implementation.

When each function module is obtained through division based on eachcorresponding function, FIG. 5 is a possible schematic structuraldiagram of the terminal (for example, a first terminal) used in theforegoing embodiments. The first terminal includes an obtaining unit 51and a determining unit 52.

The obtaining unit 51 is configured to support the first terminal inperforming process 401 in FIG. 4. The determining unit 52 is configuredto support the first terminal in performing process 402 in FIG. 4. Allrelated content of steps in the foregoing method embodiments may becited in function descriptions of corresponding function modules, anddetails are not described herein again.

When an integrated unit is used, FIG. 6 is a possible schematicstructural diagram of a first terminal used in the foregoingembodiments. The first terminal includes: a processing module 62 and acommunications module 63. The processing module 62 is configured tocontrol and manage an action of the first terminal. For example, theprocessing module 62 is configured to support the first terminal inperforming processes 401 and 402 in FIG. 4, and/or is configured toperform another process of the technology described in thisspecification. The communications module 63 is configured to supportcommunication between the first terminal and another network entity (forexample, a network device or a second terminal). The first terminal mayfurther include a storage module 61, configured to store program codeand data of the first terminal.

The processing module 62 may be a processor or a controller, such as acentral processing unit (Central Processing Unit, CPU), a generalpurpose processor, a digital signal processor (Digital SignalProcessing, DSP), an application-specific integrated circuit(Application Specific Integrated Circuit, ASIC), a field programmablegate array (Field-Programmable Gate Array, FPGA), or anotherprogrammable logical device, a transistor logical device, a hardwarecomponent, or a combination thereof. The controller/processor mayimplement or execute various example logical blocks, modules, andcircuits described with reference to content disclosed. Alternatively,the processor may be a combination of processors implementing acomputing function, for example, a combination of one or moremicroprocessors, or a combination of the DSP and a microprocessor. Thecommunications module 63 may be a transceiver, a transceiver circuit(for example, an RF circuit), a communications interface, or the like.The storage module 61 may be a memory.

When the processing module 62 is a processor, the communications module63 is an RF transceiver circuit, and the storage module 61 is a memory,the terminal in this embodiment may be the terminal shown in FIG. 2.

Further, an embodiment provides a computer program, and the computerprogram includes an instruction. When the computer program is executedby a computer, the computer can perform the data transmission method inthe processes 401 and 402.

Further, an embodiment provides a computer storage medium, configured tostore a computer software instruction used by the first terminal, wherethe computer software instruction includes any program designed forexecution by the first terminal.

The foregoing descriptions of implementations allow a person skilled inthe art to understand that, for the purpose of convenient and briefdescription, division of the foregoing function modules is used as anexample for illustration. In actual application, the foregoing functionscan be allocated to different modules and implemented according to arequirement, that is, an inner structure of an apparatus is divided intodifferent function modules to implement all or some of the functionsdescribed above. For a detailed working process of the foregoing system,apparatus, and components thereof, reference may be made to acorresponding process in the foregoing method embodiments, and detailsare not described herein again.

In the several embodiments provided in this application, it should beunderstood that the disclosed system, apparatus, and method may beimplemented in other manners. For example, the described apparatusembodiment is merely an example. For example, the module division ismerely logical function division and may be other division in actualimplementation. For example, a plurality of units or components may becombined or integrated into another system, or some features may beignored or not performed. In addition, the displayed or discussed mutualcouplings or direct couplings or communication connections may beimplemented using some interfaces. The indirect couplings orcommunication connections between the apparatuses or units may beimplemented in electronic, mechanical, or other forms.

The apparatus described as separate parts may or may not be physicallyseparate, and parts displayed as units may or may not be physical units,may be located in one position, or may be distributed on a plurality ofnetwork units. Some or all of the units may be selected based on actualrequirements to achieve the objectives of the solutions of theembodiments.

In addition, function units in the embodiments of this application maybe integrated into one processing unit, or each of the units may existalone physically, or two or more units are integrated into one unit. Theintegrated unit may be implemented in a form of hardware, or may beimplemented in a form of a software function unit.

When the integrated unit is implemented in the form of a softwarefunction unit and sold or used as an independent product, the integratedunit may be stored in a computer-readable storage medium. Based on suchan understanding, the technical solutions of this applicationessentially, or the part contributing to the prior art, or all or someof the technical solutions may be implemented in the form of a softwareproduct. The software product is stored in a storage medium and includesseveral instructions for instructing a computer device (which may be apersonal computer, a server, or a network device) or a processor toperform all or some of the steps of the methods described in theembodiments of this application. The foregoing storage medium includes:any medium that can store program code, such as a flash memory, aremovable hard disk, a read-only memory, a random access memory, amagnetic disk, or an optical disc.

The foregoing descriptions are merely specific implementations of thisapplication, but are not intended to limit the protection scope of thisapplication. Any variation or replacement within the technical scopedisclosed in this application shall fall within the protection scope ofthis application. Therefore, the protection scope of this applicationshall be subject to the protection scope of the claims.

1. A power control method implemented by a terminal, the power controlmethod comprising: obtaining configuration signaling indicating a targetreference signal that is used for determining a path loss; receiving,the target reference signal; determining, based on the target referencesignal and according to the configuration signaling, the path loss of atarget beam; and determining, based on the path loss, an uplink transmitpower for performing uplink transmission of the target beam.
 2. Thepower control method of claim 1, wherein the target reference signalcomprises at least one of a first target reference signal or a secondtarget reference signal.
 3. The power control method of claim 2, whereinthe first target reference signal comprises a terminal-specificreference signal.
 4. The power control method of claim 2, wherein thesecond target reference signal comprises a synchronization signal (SS).5. The power control method of claim 1, further comprising determiningthe uplink transmit power using a power control formula.
 6. The powercontrol method of claim 1, wherein determining the path loss furthercomprises: determining, based on the target reference signal andaccording to the configuration signaling, a received signal strength;and determining, based on the received signal strength, the path loss.7. The power control method of claim 6, wherein determining the pathloss further comprises determining, based on calculating the receivedsignal strength or filtering the received signal strength, the pathloss.
 8. The power control method of claim 7, wherein filtering thereceived signal strength comprises filtering the received signalstrength using layer-1 filtering, layer-2 filtering, or layer-3filtering.
 9. The power control method of claim 1, further comprisingobtaining parameter information required for power control, wherein theparameter information comprises a cell-specific target power, andwherein the uplink transmit power is further determined based on theparameter information.
 10. The power control method of claim 9, whereinthe parameter information further comprises a terminal-specific targetpower.
 11. The power control method of claim 1, wherein the uplinktransmission comprises at least one of transmission on a physical uplinkshared channel (PUSCH), transmission on a physical uplink controlchannel (PUCCH), transmission on a physical random access channel(PRACH), or transmission of a sounding reference signal (SRS).
 12. Apower control method implemented by a base station, the power controlmethod comprising: sending, to a terminal, configuration signalingindicating a target reference signal that is used for determining a pathloss; and sending, to the terminal, the target reference signal, whereinthe target reference signal is used for the terminal to determine thepath loss of a target beam according to the configuration signaling. 13.A terminal comprising: a memory configured to store instructions; and aprocessor coupled to the memory and configured to execute theinstructions to cause the terminal to: obtain configuration signalingindicating a target reference signal; receive the target referencesignal; determine, based on the target reference signal and according tothe configuration signaling, a path loss of a target beam; anddetermine, based on the path loss, an uplink transmit power used forperforming uplink transmission of the target beam.
 14. The terminal ofclaim 13, wherein the target reference signal comprises at least one ofa first target reference signal or a second target reference signal. 15.The terminal of claim 14, wherein the first target reference signalcomprises a terminal-specific reference signal.
 16. The terminal ofclaim 14, wherein the second target reference signal comprises asynchronization signal (SS).
 17. The terminal of claim 13, wherein theinstructions further cause the terminal to determine the uplink transmitpower using a power control formula.
 18. The terminal of claim 13,wherein the instructions further cause the terminal to determine thepath loss by: determining, based on the target reference signal andaccording to the configuration signaling, received signal strength; anddetermining, based on the received signal strength, the path loss. 19.The terminal of claim 18, wherein the instructions further cause theterminal to determine the path loss by further determining, based oncalculating the received signal strength or filtering the receivedsignal strength, the path loss.
 20. A base station comprising: a memoryconfigured to store instructions; and a processor coupled to the memoryand configured to execute the instructions to cause the base station to:send configuration signaling indicating a target reference signal to aterminal; and send the target reference signal to the terminal, whereinthe target reference signal is configured to enable the terminal todetermine a path loss of a target beam according to the configurationsignaling.